#StackBounty: #nosql What is the point of column families?

Bounty: 100

I’ve seen that NoSQL database systems like RocksDB offer a feature called column families. I roughly understand what this, but what is that actual benefit of using it? I presume it improves some look-up performance, or space locality of keys, at the very least? It wouldn’t seem to affect the actual semantics of database access, however, as far as I understand.